reactions of ions in aqueous solutions Flashcards
What happens when a salt of a transition metal is dissolved in water?
Water molecules cluster around the metal ion, forming a complex ion with an octahedral arrangement.
How many water molecules act as ligands in metal aqua ions?
Six water molecules.
What type of bond do water molecules form with the metal ion in metal aqua ions?
Coordinate bond.
Fill in the blank: M2+ + 6H2O → _______.
[M(H2O)6]2+
What are the three main types of reactions that metal aqua ions undergo?
- Hydrolysis
- Substitution
- Redox
What is hydrolysis in the context of metal aqua ions?
Loss of H+ from H2O ligands.
How does the acidity of metal aqua ions in solution change with the charge of the metal?
The higher the charge on the metal, the more acidic the solution.
What is the main species present in solution for metal aqua ions?
[M(H2O)6]n+
Why does a higher charge on the metal ion lead to stronger acidity?
Higher charge density leads to a stronger pull on electrons, breaking the O-H bond.
True or False: 3+ compounds are less acidic than 2+ compounds.
False.
What happens when a base is added to a metal aqua ion?
Further hydrolysis occurs, forming insoluble precipitates.
What do OH- ions do in the presence of metal aqua ions?
They remove hydroxonium ions, shifting equilibrium to the right.
Fill in the blank: M2+ forms M(H2O)4(OH)2 after _______.
two steps of hydrolysis
Fill in the blank: M3+ forms M(H2O)3(OH)3 after _______.
three steps of hydrolysis
What are metal hydroxides that are insoluble in water called?
Metal(II) hydroxides or metal(III) hydroxides.
What does amphoteric mean in the context of metal hydroxides?
Metal hydroxides can act as either an acid or a base.
What happens when Al(H2O)3(OH)3 reacts with a base?
It donates H+ and dissolves.
What happens when Al(H2O)3(OH)3 reacts with an acid?
It accepts H+ and dissolves.
What do metal(II) aqua ions form when they react with NaOH?
Precipitates of metal(II) hydroxides.
What do metal(III) aqua ions form when they react with NaOH?
Precipitates of metal(III) hydroxides.
What does Al(OH)3 form when it reacts further with excess NaOH?
[Al(H2O)2(OH)4]–
What do metal aqua ions form when they react with NH3?
Precipitates of metal(II) or metal(III) hydroxides.
What happens when Cu(+2) reacts with excess NH3?
[Cu(H2O)2(NH3)4]2+ is formed by ligand substitution.
What occurs when metal aqua ions react with concentrated HCl?
Substitution reactions occur, replacing H2O ligands with Cl- ligands.
